Electrical connection arrangement

ABSTRACT

An electrical connection arrangement between a contact element (13) and connection wire (12)is designed in such a way that reliable contact-making is possible in a simple manner and with the capability of automation. For this purpose, the connecting arrangement has a receptacle (11), in which the connecting wire (12) is held in the form of a winding having a plurality of turns. The contact element (13) provided with cutting edges (32) can be plugged into the receptacle (11). The outer delimitations of the turns of the connecting wire (12) and the cutting edges (32) are inclined with respect to one another in their longitudinal extent, with the result that, in the case of a plug-in movement of the contact element (13) into the receptacle (11), said contact element enters into a cutting connection on a plurality of turns of the connecting wire (12). This connection arrangement is used, inter alia, when contact is made between the connecting wires (12) of coils.

BACKGROUND OF THE INVENTION

The invention relates to an electrical connection arrangement of forretention of a connecting wire. Such a connection arrangement has beendisclosed by DE 41 40 227 A1 and relates to a device for connecting acable end, which has been cut off perpendicularly with respect to itslongitudinal axis, to a plug or socket element.

The latter has a clamping contact which penetrates the cable from theend side and is secured by means of a sleeve, which can be pushed overthe cable end, and a union nut, which presses the cable end against astop surface, the sleeve being pressed against the outer insulation ofthe cable.

As a result of its structure, this connection arrangement requires ahigh production outlay and, in addition, can be used only in the case ofa cable whose conductors comprise a wire bundle, with the result thatcables having a single wire in each case cannot be connected.

The production of connection arrangements by soldering or welding isalso known. In the case of a cable whose conductor is formed by a singlewire, this leads to poor production automation if the wire is insulated,since, depending on the type of insulation, thermal or mechanicalinsulation stripping is required, and the wire end also has to betin-coated in the case of soldering.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anelectrical connection arrangement which avoids the disadvantages of theprior art.

In keeping with these objects and with others which will become apparenthereinafter, one feature of the present invention resides, brieflystated, in an electrical connection arrangement having a receptacle forretention of a connecting wire and having a contact element forconnection of the connecting wire and for the detachable coupling to amating plug, wherein the connecting wire is arranged in form of awinding with a plurality of turns in a manner such that it can bebrought to bear against the receptacle, the contact element with atleast one cutting edge extending in a longitudinal direction of thewinding, the cutting edge and the winding delimitation opposite thelatter are inclined with respect to one another in the longitudinaldirection of the winding due to the receptacle, and in the event of aplugging movement of the contact element onto or into the receptacle,the cutting edges enter into a cutting connection with at least one ofthe turns of the connecting wire which is radially supported on thedelimitation.

In accordance with one new feature of the present invention, the contactelement is formed as a flat-pin plug having two limbs with inner sidesprovided with cutting edges in a contact section, and the cutting edgesare inclined with respect to the longitudinal axis of the contactelement.

In accordance with another novel feature of the present invention, thereceptacle is formed as a conical hole and the contact element is formedas a circular plug with a contact section having a cross-sectional areaof a polygon wherein the cutting edges extend parallel to thelongitudinal axis of the contact element.

When the electrical connection arrangement is designed in accordancewith the present invention, it has the advantage that it is possible tomake contact, with the capability of satisfactory automation, between,above all, relatively thin wires whose inherent stability isinsufficient to resist deformation of their cross section.

For this purpose, the connection arrangement has a receptacle for aconnecting wire and a contact element, it being possible to assemblethese to an end position by a simple plugging movement which can bereadily automated. In this case, the connecting wire is cut at least inpartial regions by the contact element, with the formation of a cuttingconnection, and makes reliable contact with said contact element.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a longitudinal section of a first embodiment ofan electrical connection arrangement in accordance with the presentinvention in a preassembly position and in an end position;

FIG. 2 is a view showing a cross-section of the electrical connectionarrangement in accordance with a second embodiment of the presentinvention; and

FIG. 3 is a view showing a longitudinal section of the electricalconnection arrangement of the second embodiment shown in FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENTS

A first exemplary embodiment of an electrical connection arrangement isillustrated in FIG. 1. Said arrangement has, as main components, areceptacle 11 for a connecting wire 12 and a contact element 13, whichcan be connected to the connecting wire 12 via a connecting part 14 andcan be releasably coupled to a mating plug (no longer illustrated) via aplug part 16.

The receptacle 11 is part of a housing 17 for a coil. The housing 17made of plastic has the form of a coil former, which has at the ends aflange 18 in each case, for the purpose of delimiting the winding space.One radially directed receptacle 11 for each of the two ends of the coilemerges in each case from one of the flanges 18.

The receptacle 11 is bound to the flange 18 as a connecting hook havinga holding section which is rectangular in cross section. The holdingsection 19 is adjoined by a winding section 22 having a smallercross-sectional area., which is constant in the longitudinal extent, andarranged symmetrically with respect to a longitudinal axis 21 of thereceptacle 11, a radially extending shoulder 23, which points away fromthe coil, being formed at the transition of the winding section 22 tothe holding section 19. The connecting wire 12 is wound as a winding, ina single layer having a plurality of turns, onto the winding section 22in a fixed manner and with no radial play, a start turn 24 bearingagainst the shoulder 23 and an end turn 26 being fixed in a slot (nolonger illustrated) close to the exposed end of the winding section 22.The shoulder 23 is dimensioned in such a way that it covers theconnecting wire 12 of the start turn 24 approximately up to 0.7 of thediameter of said wire, and forms a stop for the axial securing of theturns, fitted to the winding section 22, of the connecting wire 12. Theconnecting wire 12 itself is a thin winding wire without any appreciableinherent stability and with a layer of varnish as insulation.

The contact element 13 is designed as a forked, metal flat-pin plug withtwo elongate limbs 28 adjoining the contact part and arrangedsymmetrically with respect to a longitudinal axis 27 of the contactelement 13. Said limbs have a contact opening 29 between their free endsand have wedge-shaped locking hooks 31 on the outside.

The opposite inner sides of the limbs 28 extend parallel to one another,at a radial separation corresponding to the diameter of the connectingwire 12 arranged on the winding section 22, in an insertion section 33which is formed approximately over half the longitudinal extent of thelimbs 28 and starts from the contact opening 29. In a contact section34, which adjoins the insertion section 33 and reaches the plug part 16,the inner sides of the limbs are designed as cutting edges 32 and areinclined with respect to the longitudinal axis 27 of the contact element13 in such a way that their radial separation becomes continuouslysmaller in the direction of the plug part 16, until at the end it isslightly larger than the width of the winding section 22 when the latterhas no wire wound around it.

To produce the connection arrangement, the contact element 13 must beplugged by its limbs 28 onto the receptacle 11 provided with theconnecting wire 12. For this purpose, the contact element 13 is orientedin such a way that its longitudinal axis 27 is aligned with thelongitudinal axis 21 of the receptacle 11.

In the left-hand part of FIG. 1, the contact element 13 is in apreassembly position, in which it is pushed so far onto the receptacle11 that the point of transition between the insertion section 33 and thecontact section 34 is situated at the end turn 26. In this case, thelocking hooks 31 are plunged into a guide channel 36, which is arrangedin the flange 18 and extends symmetrically with respect to thelongitudinal axis 21 of the receptacle 11, and are bearing against thewall of said guide channel.

When the contact element 13 is plugged further onto the receptacle 11provided with the connecting wire 12, the cutting edges 32 come intocontact with the turns of the connecting wire 12 and, owing to theirhigher strength and as a result of their inclination with respect to thelongitudinal axis 27, they cut into the turns of the connecting wirewinding. In the process, the insulation of the connecting wire 12 is cutthrough and said connecting wire makes electrical contact with thecontact element 13. Spreading and deflection of the limbs 28 areprevented due to their guidance by means of the locking hooks 31 andparts of the insertion section 33 in the guide channel 36, anddeflection of the thin, weak connecting wire 12 is prevented due to itssupport on the receptacle 11. The winding of the connecting wire issecured against displacement in the axial direction due to the shoulderwhich points counter to the plugging direction of the contact element13.

At the end of the guide channel 36, which is radially constricted beforethis region, the locking hooks 31 snap on behind complementary lockingshoulders 37 and lock the connection arrangement in the end position, asillustrated in the right-hand half of FIG. 1.

In the end position, as a result of the inclination of the cutting edges32 with respect to the longitudinal axis 27 of the contact element 13,on the one hand, and due to the turns, arranged parallel to thelongitudinal axis 21 of the receptacle 11, of the connecting wire 12,the end winding is cut and makes electrical contact to the greatestdegree, the subsequent winding to an increasingly lesser degree and thestart winding 24, finally, is cut and makes electrical contact slightlyor even not at all. It is thus achieved that in the course of the turnsfrom the end turn 26 to the start turn 24 the deformation of theconnecting wire 12 by the contact element 13 becomes smaller and smallerand hence the risk of the connecting wire 12 breaking decreases in thedirection of the start turn 24 and hence in the direction of the coil.

The more turns there are on the winding section 22, the larger is thecontact area between the contact element 13 and the connecting wire 12,with appropriately selected inclination of the cutting edges 32 withrespect to the longitudinal axis, two partial contact areas arising foreach cut turn in this exemplary embodiment.

In this arrangement, the cross section of the winding section ispreferably oval or rectangular with rounded narrow sides, in order toprovide support for the connecting wire in the region of thelongitudinal sides against the cutting edges which act there. Inprinciple, this type of contact-making is possible even with one cuttingedge.

In the second exemplary embodiment, the contact element 13 according toFIG. 2 is designed as a circular plug. The contact section 34 thereof isdesigned as a prismatic square 41 with longitudinal edges which form thecutting edges 32. As an alternative, the contact section 34 can also bedesigned as a prism with a cross-sectional area of another polygon.

The contact element 13 is supported according to FIG. 3 in an insulatinghousing 42, which is arranged above the housing 17 of the coil andprotects the latter. The contact element 13 can be displaced along itslongitudinal axis 27 in a guide hole 43 in the insulating housing 42.The following are arranged in alignment with the guide hole 43: a blindhole 46 in a wall 44 of the housing 17, a pin 47, which issues from thewall 44, and, 10 in a lower part 48, which is situated underneath thehousing 17, is made of insulating material or plastic and on which thecoil is fixed, the receptacle 11 and a passage hole 49.

Whereas the passage hole 49 is dimensioned in such a way that it canaccommodate the pin 47 with movement play and the square 41 with a pressfit, the receptacle 11 is designed as a conical hole, constrictingtoward the passage hole 49, with an inner wall 51. The receptacle 11,which has, over its entire longitudinal extent, a larger radialdimension than the passage hole 49, adjoins the latter with the shoulder23, which is dimensioned as in the first exemplary embodiment.

The connecting wire 12 is fitted to the pin 47 in one layer with aplurality of turns, the start turn 24 bearing against the wall 44 of thehousing 17 and the end turn 26 being fixed close to the exposed end ofthe pin 47.

The pin 47 is connected to the rest of the housing 17 via four thin webs52 which are distributed uniformly over the periphery of said pin andare designed as desired breaking points.

If the contact element 13 is guided from a preassembly position,according to the left-hand half of FIG. 3, toward the pin 47, then thewebs 52 break under a severe pressure load and the pin 47 is pushed pastthe shoulder 23 into the passage hole 49. During this movement, the endturn 26 comes to bear against the shoulder 23 which forms an axial stopfor the turns of the connecting wire 12. In the event of continuedmovement, all the turns of the thin, weak connecting wire 12 arestripped off from the pin 47, pressed against the inner wall 51 of thereceptacle 11 by the square 41 and radially supported there. The angleof inclination of the inner wall 51 with respect to the longitudinalaxis 21 of the receptacle 11 and the respective radial extent, which haschanged over the longitudinal extent, of the receptacle 11 aredimensioned in such a way that when the square 41 reaches the endposition according to the right-hand half of FIG. 3, it cuts, by meansof the four cutting edges 32, and makes contact with the end turn 26 tothe greatest degree and the start turn 24 only slightly or not at all.

Consequently, as in the first exemplary embodiment, the connecting wire12 is mechanically loaded only slightly toward the coil and any risk ofbreaking on the coil is avoided.

Compared with the first exemplary embodiment, the contact area betweenthe contact element 13 and the connecting wire 12 is doubled in thisembodiment, since the cutting edges 32 form four contact areas for eachcut turn.

The end position of the connection arrangement is secured by a press fitof the contact section 34 in the passage hole 49 or by radially directedsealing ribs 53 which are fitted to the connecting part 14 and areintroduced into the guide hole 43, with a press fit, in the endposition.

A common feature of both exemplary embodiments is the fact that contactcan be made easily, using a procedure which can be carried out in ajoint operation and can be automated, between the contact elements 13and the thin connecting wires 12, which have no appreciable inherentstability, due to the configuration of the two receptacles 11 forradially supporting the connecting wires 12 of the two winding ends ofthe coil and of the assigned contact elements 13, and that it ispossible to achieve reliable contact-making due to the large contactareas.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in anelectrical connection arrangement, it is not intended to be limited tothe details shown, since various modifications and structural changesmay be made without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:
 1. An electrical connectionarrangement, comprising a connecting wire; a receptacle for retainingsaid connecting wire; a contact element for connecting to saidconnecting wire and for detachably coupling to a mating plug, saidconnecting wire being arranged in form of a winding having a pluralityof turns so as to bear against said receptacle, said contact elementhaving at least one cutting edge extending in a longitudinal directionof said winding, said cutting edge and a delimitation of said windingopposite to said cutting edge being inclined relative to one another inthe longitudinal direction of said winding so that in the event of aplugging movement of said contact element onto or into said receptacle,said cutting edges enter into a cutting connection with at least one ofsaid turns of said connecting wire which is radially supported on saiddelimitation, said receptacle and said contact element having alignedlongitudinal axes so that the plugging movement of said contact elementonto or into said receptacle provided with said connecting wire takesplace as far as an end position in which said contact element and saidreceptacle are fixed relative to one another; means for fixing saidcontact element an said receptacle with one another, said receptaclebeing formed as a connecting element of a coil with a winding sectioncarrying said connecting wire in one layer and a cross-sectional areawhich is essentially constant in direction of a longitudinal axis ofsaid receptacle, said contact element being formed as a flat-pin plughaving two limbs with inner sides provided with cutting edges formed ina contact section, said cutting edges being inclined relative to thelongitudinal axis of said contact element.
 2. An electrical connectionarrangement as defined in claim 1, wherein said receptacle has ashoulder pointing counter to the plugging direction of said contactelement and arranged so that said winding bears against said shoulder.3. An electrical connection arrangement as defined in claim 1, whereinsaid fixing means include complementary locking elements.
 4. Anelectrical connection arrangement as defined in claim 1, wherein saidfixing means include a press fit.
 5. An electrical connectionarrangement, comprising a connecting wire; a receptacle for retainingsaid connecting wire; a contact element for connecting to saidconnecting wire and for detachably coupling to a mating plug, saidconnecting wire being arranged in form of a winding having a pluralityof turns so as to bear against said receptacle, said contact elementhaving at least one cutting edge extending in a longitudinal directionof said winding, said cutting edge and a delimitation of said windingopposite to said cutting edge being inclined relative to one another inthe longitudinal direction of said winding so that in the event of aplugging movement of said contact element onto or into said receptacle,said cutting edges enter into a cutting connection with at least one ofsaid turns of said connecting wire which is radially supported on saiddelimitation, said receptacle and said contact element having alignedlongitudinal axes so that the plugging movement of said contact elementonto or into said receptacle provided with said connecting wire takesplace as far as an end position in which said contact element and saidreceptacle are fixed relative to one another; means for fixing saidcontact element an said receptacle with one another, said receptaclebeing formed as a conical hole, said contact element being formed as acircular plug with a contact section having a cross-sectional area of apolygon with cutting edges extending parallel to a longitudinal axis ofsaid contact element.
 6. An electrical connection arrangement as definedin claim 5, wherein said receptacle has a shoulder pointing counter tothe plugging direction of said contact element and arranged so that saidwinding bears against said shoulder.
 7. An electrical connectionarrangement as defined in claim 5, wherein said fixing means includecomplementary locking elements.
 8. An electrical connection arrangementas defined in claim 5, wherein said fixing means include a press fit.